Download our iOS/Android app now!


If it’s just you and a pig on a desert island surely you would eat the pig to survive?


Quick Responses

That’s a difficult question. If it’s just you and a child on a desert island would you eat the child to survive?


That’s an interesting thought experiment. It is designed to test the Ethics of Emergencies and whether they differ in scope from everyday ethics. That the survivors of Flight 571 turned to cannabalism to survive in an emergency was not a mandate for cannabalism under everyday conditions. Similarly, even if a vegan did kill and eat the pig in an emergency this does not justify the unnecessary killing of animals under normal conditions.

Detail - Analytic

How does the argument go?

This thought experiment is usually presented as some sort of “Gotcha”.

If it’s just you and a pig on a desert island surely you would eat the pig so you could survive yourself? Then you wouldn’t be vegan anymore would you?
Followed by: So if you (the vegan) choose to eat the pig, then that’s no different from me eating pork when I choose.

This line of reasoning is both false (as discussed shortly) and shows a misunderstanding of the scope and nature of the thought experiment:

The thought experiment

The following is a more complete version of the thought experiment:

A ship sinks and there are only two survivors. You and the other survivor have washed up on a small rocky island. You know when the next boat will pass and will be able to signal help. However, you will not survive till then unless you kill and eat your companion.

Consider that the other survivor is: a child, an adult; your pet dog; a pig. Work through the thought experiment 4 times. Each time replace the other survivor with one of the options from the list.

  • Do you act the same way on each occasion?
  • Why/Why not?

(When rescued it will be assumed the other washed up dead. In the case where the other was a human you will never be charged with their murder)

Don’t sidestep the issue!

The important thing about thought experiments is that you think about them. Don’t rush at justifying an answer; it’s more important to ponder the moral implications.

Some of the sidesteps that should be avoided:

  • I’ll eat what the pig’s eating. No, there is absolutely no other food source.
  • What if the other tried to eat you, so you had to kill them in self-defence?
  • While you wait for rescue, befriend the pig who would then provide company much like your pet cat or dog would? This might deflect the argument on to another interesting discussion but it still sidesteps this important thought experiment. You will not survive until rescued unless you kill the other survivor.
  • This couldn’t happen because… (numerous reasons are presented). Yes, the thought experiment presents an improbable scenario but one that is logically possible. However, it really does not matter if the event could occur. Thought experiments are artificial constructs designed to test specific moral principles; you might argue that all thought experiments are invalid but it is far more interesting to engage and consider the implications.
  • You can’t kill the humans; that’s murder! (Perhaps, but let’s not confuse legality with morality. Is the action morally justified? …and remember you will never be charged with murder.)

What’s the answer?

The temptation with thought experiments is to rush to an answer and then be forced to turn cartwheels in an attempt to justify that answer. Consider:

  • Would you kill the animal but not a child? Is that just because they are human? Are you making a claim of human superiority?
  • Does killing/eating the pig in any way show a weakness in veganism? (No, it doesn’t, as we’ll demonstrate shortly).
  • Does killing and eating the child endorse cannabalism?
  • What moral principle are you applying?

The purpose of thought experiments is to make you think about the moral implications and principles.

It’s worth repeating one more time; the purpose here is not to force you to answer the questions. It’s to get you to engage with the concepts and consider the moral implications.

Suicide is painless?

The difficulty, my friends, is not to avoid death, but to avoid unrighteousness - The Apology of Socrates by Plato.

Co-Author Valerie has suggested that suicide, although extreme, could be an option to consider. As a vegan, it’s a pretty hard decision to make to deliberately kill a pig, or any other animal, even in order to ensure my survival. While I could regard my own life as more important than the pig’s, I recognise that the pig values their life as much as I value mine. So, the choice to take the life of another sentient being seems an impossible dilemma. The alternative thought is that of suicide; why kill the pig only to live the rest of my life depressed because my actions didn’t live up to my morals?

This echoes Socrates’ thoughts that death is preferable to sacrificing our deeply held morals. This is possibly a noble ideal as, if you kill yourself and the other survivor is another human then you provide them with the means of survival. But, does the same logic apply when your companion is an animal? Yes, they can eat your remains and live a little longer but they won’t be rescued so will slowly die from dehydration and starvation.

This opens several new and interesting questions:

  • Even if you decide to commit suicide wouldn’t it be kinder to kill the animal first, rather than allowing it to suffer?
  • If you do mercy-kill the animal (to avoid any unnecessary suffering) does suicide remain your option? That is; is it wrong for a vegan to eat the flesh of the now dead animal to survive?

Once again, it is not necessary to answer these questions only to consider the moral implications of the thought experiment.

It is a Fallacy not an Argument

While a fascinating thought experiment, when presented as an anti-vegan argument, it reveals a fallacy. The carnist’s argument runs something like:

[Point 1] If it’s just you and a pig on a desert island surely you would eat the pig so you could survive?
[Point 2] Then you wouldn’t be vegan anymore would you?
[Point 3] So if you (the vegan) choose to eat the pig, that’s no different from me eating pork when I choose.

In more analytical form; this implies that if you do a specific action under emergency conditions then that action is justified under any conditions. This is clearly false. As we noted earlier, the survivors of Flight 571 turned to cannabalism, eating the deceased to survive, but this was not a mandate for cannabalism under everyday conditions.

It is important to differentiate between the rules of conduct in an emergency situation and the rules of conduct in the normal conditions of human existence. This does not mean a double standard of morality: the standard and the basic principles remain the same, but their application to either case requires precise definitions. - The Ethics of Emergencies by Ayn Rand

Let’s recall the definition of veganism. A philosophy and way of living which seeks to exclude — as far as is possible and practicable - all forms of exploitation of, and cruelty to, animals for food…

In an emergency situation the unlikely, but possible, scenario where you must choose between your own life and the life of another could occur. If the companion was an animal would the vegan kill to survive? I have no idea and nor, I expect, does anyone unless they were actually in that situation. But, whichever action is chosen, it in no way negates the principles of veganism.

In our thought experiment it’s not possible to survive without killing the other, so the vegan might:

  • place their own life ahead of their companion’s, in this emergency, without feeling they had betrayed their vegan principles.
  • consider the principles of veganism so important that a slow death from dehydration is a preferable option.

Final thoughts

It is unfortunate this fascinating thought experiment is misused as an anti-vegan argument. When it is, it becomes a fallacy and the important implications for moral principles are lost.

The Authors have no certainty about how they would act if marooned on an island with a pig; would their survival instincts or values prevail? What we are certain about is that, regardless of what occurs on the island, it in no way justifies or condones the unnecessary slaughter of millions of animals for nothing more than their taste.


  • The Apology by Plato translated by Benjamin Jowett also available online.
  • The Ethics of Emergencies by Ayn Rand in Normative Ethics: The Virtuos Egoist also available online.

Article Contributors

Dr Tery Hardwicke
Valerie Redfern
Co author
Sam Martin
Deb Hardwicke